Weeds cause tremendous global economic losses by reducing crop yields and lowering crop quality. Worldwide, agronomic crops must compete with a vast variety of weed species. Although there are a number of commercial herbicides available, crop safety and efficacy over a broad spectrum of weed species remain challenges in modern agronomic practice. Accordingly there is an ongoing need to discover and develope more crop-selective and broader spectrum herbicidal agents.
Thiochroman- and dihydrobenzothiophene-hydroxypyrazole derivatives and their herbicidal use are described in U.S. Pat. No. 5,607,898 and WO 97/08164. However, thiochroman and dihydrobenzothiophene substituted methylene pyrazolinone compounds and their use as broad-spectrum, crop-selective herbicides are not described therein.
Therefore, it is an object of this invention to provide highly effective broad spectrum herbicidal methylene pyrazolinone compounds.
It is also an object of this invention to provide a method for the control of a broad spectrum of undesirable plant species.
It is a further object of this invention to provide a method for the selective control of undesirable plant species in the presence of a crop.
These and other objects and features of the invention will become more apparent from the detailed description thereof set forth hereinbelow.
The present invention provides thiochroman-and dihydrobenzothiophene-substituted methylene pyrazolinone compounds of formula I 
wherein
m is zero or 1;
R1, R2, R3 and R4 are each independently H, C1-C4 alkyl, C1-C4 haloalkyl or C2-C4 alkoxyalkyl;
R5 is C1-C3 alkyl, C3-C4 alkenyl or C3-C4 haloalkenyl;
R6 is H, halogen, CN, C1-C4 alkyl, C2-C4 alkenyl, C1-C4 alkoxyalkyl or C1-C4 alkoxycarbonyl;
X is CR7R8, CHOR9, Cxe2x95x90NOR10, Cxe2x95x90NNR16R17, Cxe2x95x90O or C(OR9)2;
R7 is H, C1-C4 alkyl or C1-C4 haloalkyl;
R8 is H, C1-C4 alkyl, C2-C4 alkenyl, C2-C4 alkynyl or C1-C4 alkoxyalkyl;
R9 and R10 are each independently H or C1-C6 alkyl optionally substituted with one or more C2-C6 alkenyl, C2-C6 alkynyl, C1-C6 haloalkyl or C3-C6 cycloalkyl groups;
Y is O, S, SO or SO2;
Z is H, halogen, C1-C4 alkyl, C1-C4 haloalkyl, C2-C4 alkoxyalkyl, C1-C4 alkoxy or C1-C4 haloalkoxy;
p is an integer of 1, 2 or 3;
G is OR11, OCH2COR11, SCH2COR11, OCN2CSR11, SCH2CSR11, OCOR11, SCOR11, OCSR11, SCSR11, S(O)nR12, NR13R14, P(O) (OR15)2, halogen, CN, SCN, 
n is zero, 1 or 2;
R11 and R12 are each independently C1-C6 alkyl, C1-C6 haloalkyl, C2-C6 alkenyl, C2-C6 haloalkenyl, C2-C6 alkynyl, C2-C6 haloalkynyl, C1-C6 alkoxyalkyl, benzyl optionally substituted with one to three halogen, C1-C6 alkyl, C1-C6 alkoxy or C1-C6 haloalkyl groups or phenyl optionally substituted with one to three halogen, C1-C6 alkyl, C1-C6 alkoxy or C1-C6 haloalkyl groups;
R13 and R14 are each independently H, C1-C6 alkyl, C3-C6 alkenyl, C3-C6 alkynyl, or R13 and R14 may be taken together with the atom to which they are attached to represent a four- to seven-membered ring optionally interrupted by oxygen, sulfur, or nitrogen and optionally substituted with one to three halogen or C1-C6 alkyl groups;
R15 is C1-C6 alkyl;
R16 is H or C1-C6 alkyl;
R17 is H, C1-C6 alkyl, C1-C6 haloalkyl, C2-C6 alkoxycarbonyl, C2-C6 alkylcarbonyl, COR18 or phenyl optionally substituted with one to three C1-C3 alkyl, halogen, CN or NO2 groups, or R16 and R17 may be taken together to represent xe2x95x90C(C1-C3 alkyl)2;
R18 is phenyl optionally substituted with one to three C1-C3 alkyl, halogen, CN or NO2 groups, or a 5-to 6-membered aromatic heterocyclic ring optionally substituted with one to three C1-C3 alkyl, halogen, CN or NO2 groups;
M is a transition metal or an alkaline-earth metal; and
q is an integer of 1, 2 or 3; or the geometric or optically active isomers thereof.
The present invention also provides herbicidal compositions and methods and a process to prepare a compound of formula I.